In ch 4 of U, Mill seeks to prove that the utility principle is true. Does he succeed?
2. What kind of proof is the proof of utility? (I-3, IV-1).
L1: distinction between ethics and meta-ethics. Ethics: what is the right/wrong thing to do; meta-ethics: how do we reach judgements as to what is morally right and wrong. To ask what kind of proof we may and must construct, for the view that happiness is the only thing desirable, is to ask a meta-ethical question.
Mill’s philosophical method:
Rejection of intuitionism (I-3). Mill’s inductive meta-ethics: according to Mill, matters of fact (about the world) must be settled by ‘direct appeal to the faculties which judge of fact – namely, our senses, and our internal consciousness.’ (IV-1). More precisely: one cannot prove by reasoning that first principles are true. This goes for scientific knowledge, and for ethics. Thus: ‘the only proof capable of being given that an object is visible, is that people actually see it. The only proof that a sound is audible, is that people hear it: and so of the other sources of our experience. In alike matter….the sole evidence it is possible to produce that anything is desirable, is that people do actually desire it.’ (I-3). This is one of the most famous, and disputed, statements to come from Mill’s pen.
As applied to U: ‘if the end which the utilitarian doctrine proposes to itself were not, in theory and in practice, acknowledged to be an end, nothing could ever convince any person that it was so. No reason can be given why the general happiness is desirable, except that each person, so far as he believes it to be attainable, desires his own happiness. This, however, being a fact, we have not only all the proof which the case admits of, but all which it is possible to require, that happiness is a good: that each person’s happiness is a good to that person, and the general happiness, therefore, a good to the aggregate of all persons.’ (I-3). More strongly still, happiness is the only thing that people desire.
Distinguish two lines of interpretation/criticism: Mill’s method (by way of an analogy with knowledge of the external world) and his application of the method to U. Here we focus on the first. A standard criticism: Moore’s Principia Ethica. According to Moore, Mill fails to spot a crucial difference between that which is visible, and that which is desirable. To say that an object is visible is to say that it is capable of being seen (by definition.) And if we can point to people who actually can see that object, then we have evidence that the object is visible. But the idea of ‘desirable’ is very different. When we say that something is desirable, we do not mean ‘it is capable of being desired.’ We mean ‘it is an appropriate object of desire’. The problem (for Moore) is that it does not follow from the fact that people actually desire that object, that it is an appropriate object of desire (e.g.: drugs.)
Standard reply to Moore (See, e.g, Crisp, 1997, 73ff; Hall, 1949; Skorupski, 1989, 286). Mill was perfectly aware of the definitional differences between ‘visible’ and ‘desirable’, and only meant to say what he actually does say, namely that ‘the only evidence’ that we have of something being an appropriate object of desire is that people do actually desire it. That claim is entirely compatible with the statement ‘x is desired by people, but it is not an appropriate object for desire.’
Still, for Mill’s argument to work, it must be the case that the everyone does actually desire happiness. More than that: it must be the case that the following three claims are true:
1. Happiness is desirable because everyone desires it for himself/herself.
2. It follows from the claim that happiness is desirable to each person (for themselves), that the general happiness is a good to the aggregate of all persons.
3. Happiness is the only thing that people desire, and therefore the only criterion for morality.